Suspension spring



March 214, 1933. p* A CARTERET 1,902,394

SUSPENSION SPRING Filed April 22, 1930 Fig. 4.

d /NveN TML Patented Mar. 21, 1933 leuzen tres e PAUL ADOLPHE cnnfrnrni'.i,k or NEUILLY SUR SEINE, FRANCE-1 SUSPENSION SEZRING y y Application lled April 22, 1930, Serialklo. 446,330, and in France October 28, 1929.

The present invention relates to improvements inv springs, particularly suspension springs for motor vehicles, whereby the n oscillations of these springs are autoiiiati U call damped.

.Tlie invention is essentially characterized by the combination of two superposed'leaves one of which is` connected at one end to the chassis, While the other leaf has its correo sponding end movable and guided by means of double shackles or of slides, so that the movement of yielding and recovery of this spring produce friction between these leaves by means of which the oscillations of this spring are rapidly damped.

The invention comprises all the modes of construction in which the above combination is found, which combination maybe either single or double or associated with other friction elements or with counter leaves serving to complete the spring.

The invention is clearly illustrated inthe accompanying drawing, in which Fig. 1 is a Side elevational view of one form of the improved supporting spring. Fig. 2 is a top plan detail of the spring leaves with the securing means removed.

Fig. 3 is a fragmentary elevational detail of the arrangement shown inllig. 1

showing the action of one of the supporting shackles, and g Fig. 4 is a side elevational View partly in section of another form of supporting spring. v l

Similar characters of reference are employed in all of the above described views to indicate corresponding parts.

Referring now, more particularly to the drawing, there is provided two leaf springs Z and f arranged in superposed relation with each other, the spring Zhaving one end a pivoted to the forwardv end of the chassis while the opposite endl b is free to move i being pivoted to the outer end of a link jl in turn pivoted to a bracket suspended from the chassis. The other leaf spring f has its opposite end pivoted to the pivot point of the link jl as at cZ while the other end'c is free to move relative to the leaf spring Z being pivoted at the outer end of a link j the inner end of which is pivoted at the fixed point of the support of the leaf spring Z.

As -theleaves Z and j are pivoted in opposite Y directions to each other, when the spring yields 'they slide with respectto each 55 other, on condition Vhowever that at least one* of the leaves can slide with respect to thel assembly bolt and in spite ofthe clamping action v.which the latter producesj-"In this. connection it is to be noted that the'ends 60 of the leaves are reverselypcurved at the points where they arevmounted. 'l

Care is therefore taken vto form aslot e in one of these leaves,` vfor `example in the leaf f (Figure 2),'in order to permitv it toslide, 65` in Vwhich slot is lodged a distance piece in the formfof a plate g the thickness of which isV a little greater. than that of the leaf f which istraversed by the assembly bolt.l

j In Figure 2 `will further be seen a certain 70 number of lubricating holes distributed over the Whole surface of the leaf for'the purpose of .lubrication Y Fig. 4 shows a constructional modification in which the free ends of the` leaves, instead of being guided by shackles, bear against rollers js, jt. Y n D With the spring thus constructed, when it yields, the leaf Z lengthens and produces so an. energetic friction upon the leaf 1which lengthens in `the reverse direction andis in rubbing contact over the whole of its "sun y face. i

`lf on the contrary the spring expands by '85 curving more (particularly as the resultgof n a sudden impact) the leaves move more and more in opposite directions and their mue. tual pressure increases with theincrea'se in" curvature of the leaves.k vCare is taken moreover to give the leaf f an initialcurvature inthe reverse direction to that of the other leaves, as is done for the Asaine purpose, with the counter leaves of the ordinaryspings.p,

Moreover whenv the spring Vbeconiesin. curved, as stated above, the shackle inclines towards lthe left, and pressesthe leafZ more strongly upon the leaf f, whichpressure lis measuredrat each moment'by the height 71100 as is clearly shown in Figure 3, which shows in detail one of the ends of the spring.

The same is the case for the shackle jg. The damping is thus constantly propor- 5 tional to the amplitude of the oscillations.

The new spring thus forms a powerful brake, which promptly and eectively clamps the oscillations. The braking action due to the friction is increased as explained above by the initial curvature of the leaves and by the play of the shackles.

It will be noted that the new springs comprise no weak point -nor any break in cont-inuity over the whole of their length.

They permit the shock absorbers to be dispensed with because they perform at the same time the function of springs and that of shock absorbers. Moreover, they prevent the movements of rolling and shimmy.

In fact, it willbe noted that the entire spring is attached to the chassis by the fixed axes ca (Z of the two main leaveswithout any joint, thus eliminating the transverse reactions which produce rolling andV shiinmy, so that the vehicle holds the road more satisfactorily; besides, the double main leaf reinforces the'spring and constitutes a security element. Y, The springs maintain their ordinary appearance and the shock absorbers, their littings, their assemblage, their adjustmentand their inconveniences are eliminated.

The arrangements described above are naturally only given by way of example and 353 all the details of construction and embodiment may vary in all cases without on that account going outside the scope of the invention.

I claim l. A suspension spring comprising two leaves each of which is secured at one end to a fixed point while the other end is free and positioned adjacent the fixed end of the other leaf, one of said leaves being provided 45.1 with a slot, and a stationary spacing plate mounted in the slot allowing relative longitudinal movement of the two leaves.

2. A spring comprising two leaves one'of which has one end fixed while the opposite lend is mounted for movement while the other leaf has one end fixed near the movable end of the first leaf and its opposite end mounted for movement, said leaves being movable .securing means.

mounted in the slot and secured relatively to said solid spring, and means securing the leaves to permit said relative movement.

4. A suspension spring comprising two superposed leaves each having one end secured to the chassis and its opposite end free, the fixed end of the spring being remote from each other, securing means for the middle portions of the leaves, one of the leaves being provided with a slot, and a spacing plate mounted in the slot for allowing relative longitudinal movement of the two leaves and being fixed to the securing means.

5. A spring comprising two main leaves 'having reversely curved ends and movable relative to each other and in frictional vcontact with each other their entire length, securing means associated `with the middle portions of the leaves, one of the leaves being solid and the other being provided with a slot, a distance piece Amounted in. the slot,

and an adjustable bolt engaged through the,

slot forlanchoring lthe distance piece to the The foregoing specification of my improvements in suspension springs signed by me this 11 day of April, 1930.

vrAUL ADoLPHE C'ARTERET.

' ico in directions opposite each other over their 513i entire length` so as to be in friction with each other over their entire extent, and means for securing the free ends ofA these two leaves to the chassis in a manner that each of the two leaves is guided on the two free ends.

3. A spring comprising two main leaves having reversely curved ends movable relative to-each other over the entirelength, and in friction with each other over their entire' extent, one leaf` being solid and the other 65- being provided with a slot, a'distance piece 

